The impeller blade assembly in this example is a subsystem of a gas turbine engine used in aerospace applications.
The following model shows a cyclically symmetric sector of a single centrifugal impeller blade:
The model consists of a shroud and an impeller blade assembly with a sector angle of 27.692 degrees. The full model is composed of 13 primary blades and splitters, as shown:
Modal, perturbed prestressed modal with linear and nonlinear base static solution, full-harmonic, perturbed prestressed full-harmonic with nonlinear base static solution, and perturbed prestressed mode-superposition harmonic analyses with nonlinear base static solution are performed on the cyclic-sector model.
The perturbed modal cyclic symmetry analysis includes the initial prestressed condition from both the linear and nonlinear static analyses. The initial stress state with the linear static solution is produced by the spinning impeller assembly as well as the pressure load applied on the impeller blade. The initial stress state with the nonlinear static analysis is produced by the spinning impeller blade, a pressure load applied on the impeller blade, and thermal loading applied on all nodes of the impeller blade assembly model.
The perturbed full-harmonic and perturbed mode-superposition harmonic cyclic symmetry analyses include the initial prestressed condition due to the nonlinear static analysis. The initial stress state is produced by the spinning of the impeller assembly and thermal loading applied on all nodes of the impeller blade assembly model.
Modal, perturbed modal, full-harmonic, and perturbed full-harmonic analyses of the full (360-degree) model are also performed to validate the accuracy of cyclic-sector model results.